/**
 * Software License, Version 1.0
 * 
 * Copyright 2003 The Trustees of Indiana University.  All rights reserved.
 * 
 *
 *Redistribution and use in source and binary forms, with or without 
 *modification, are permitted provided that the following conditions are met:
 *
 *1) All redistributions of source code must retain the above copyright notice,
 * the list of authors in the original source code, this list of conditions and
 * the disclaimer listed in this license;
 *2) All redistributions in binary form must reproduce the above copyright 
 * notice, this list of conditions and the disclaimer listed in this license in
 * the documentation and/or other materials provided with the distribution;
 *3) Any documentation included with all redistributions must include the 
 * following acknowledgement:
 *
 *"This product includes software developed by the Community Grids Lab. For 
 * further information contact the Community Grids Lab at 
 * http://communitygrids.iu.edu/."
 *
 * Alternatively, this acknowledgement may appear in the software itself, and 
 * wherever such third-party acknowledgments normally appear.
 * 
 *4) The name Indiana University or Community Grids Lab or NaradaBrokering, 
 * shall not be used to endorse or promote products derived from this software 
 * without prior written permission from Indiana University.  For written 
 * permission, please contact the Advanced Research and Technology Institute 
 * ("ARTI") at 351 West 10th Street, Indianapolis, Indiana 46202.
 *5) Products derived from this software may not be called NaradaBrokering, 
 * nor may Indiana University or Community Grids Lab or NaradaBrokering appear
 * in their name, without prior written permission of ARTI.
 * 
 *
 * Indiana University provides no reassurances that the source code provided 
 * does not infringe the patent or any other intellectual property rights of 
 * any other entity.  Indiana University disclaims any liability to any 
 * recipient for claims brought by any other entity based on infringement of 
 * intellectual property rights or otherwise.  
 *
 *LICENSEE UNDERSTANDS THAT SOFTWARE IS PROVIDED "AS IS" FOR WHICH NO 
 *WARRANTIES AS TO CAPABILITIES OR ACCURACY ARE MADE. INDIANA UNIVERSITY GIVES
 *NO WARRANTIES AND MAKES NO REPRESENTATION THAT SOFTWARE IS FREE OF 
 *INFRINGEMENT OF THIRD PARTY PATENT, COPYRIGHT, OR OTHER PROPRIETARY RIGHTS. 
 *INDIANA UNIVERSITY MAKES NO WARRANTIES THAT SOFTWARE IS FREE FROM "BUGS", 
 *"VIRUSES", "TROJAN HORSES", "TRAP DOORS", "WORMS", OR OTHER HARMFUL CODE.  
 *LICENSEE ASSUMES THE ENTIRE RISK AS TO THE PERFORMANCE OF SOFTWARE AND/OR 
 *ASSOCIATED MATERIALS, AND TO THE PERFORMANCE AND VALIDITY OF INFORMATION 
 *GENERATED USING SOFTWARE.
 */
package cgl.narada.wsinfra.util;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;

import org.apache.xmlbeans.XmlException;

import cgl.narada.wsinfra.schemas.addressing.EndpointReferenceDocument;
import cgl.narada.wsinfra.schemas.addressing.EndpointReferenceType;
import cgl.narada.wsinfra.schemas.soap.EnvelopeDocument;


/** A utility class to Marshall and Unmarshall object and object bytes 
    @author Shrideep Pallickara
    $Date: 2005/07/29 22:41:29 $
    $Revision: 1.3 $
 */

public class MarshallingUtils {
  
  public static final MarshallingUtils instance = new MarshallingUtils();
  
  private String moduleName = "MarshallingUtils: ";

  private MarshallingUtils() {}
  
  public static MarshallingUtils getInstance() {
    return instance;
  }

  /** Marshall an object into a byte stream */
  public byte[] marshall(Object object) throws IOException {
    ByteArrayOutputStream baOutputStream = new ByteArrayOutputStream();
    ObjectOutputStream oOut = new ObjectOutputStream(baOutputStream);
    oOut.writeObject(object);
    byte[] objectBytes = baOutputStream.toByteArray();
    return objectBytes;
  }


  /** Unmrahsall an object from a byte stream */
  public Object unmarshall(byte[] objectBytes) 
    throws IOException, ClassNotFoundException {
    
    ByteArrayInputStream baInputStream = 
      new ByteArrayInputStream(objectBytes);
    ObjectInputStream oin = new ObjectInputStream(baInputStream);
    Object object = oin.readObject();
    
    return object;
  }

  /** Writes an object onto a DataOutputStream */
  public void writeObjectToStream(Object object, DataOutputStream dout) 
    throws IOException {
    byte[] objectBytes = marshall(object);
    dout.writeInt(objectBytes.length);
    dout.write(objectBytes);
  }
  
  
  /** Reads an object that was written using the <i>writeObject(object, 
      DataOutputStream)</i> from a DataInputStream */
  public Object readObjectFromStream(DataInputStream din) 
    throws IOException, ClassNotFoundException {
    byte[] objectBytes = new byte[din.readInt()];
    din.readFully(objectBytes);
    return unmarshall(objectBytes);
  }

  
  /** Reads a String from the underlying dataInput Stream */
  public String readStringFromStream(DataInputStream din) 
    throws IOException {
    int numToRead = din.readInt(); 
    if (numToRead == 0) {
      return null;
    }
    
    byte[] toReadBytes = new byte[numToRead];
    din.readFully(toReadBytes);
    String readString = new String(toReadBytes);
    return readString;
  }


  /** Writes a String to the underlying stream */
  public void writeStringToStream(String toWrite, DataOutputStream dout) 
    throws IOException {
    if (toWrite == null) {
      dout.writeInt(0);
      return;
    }

    byte[] toWriteBytes = toWrite.getBytes();
    dout.writeInt(toWriteBytes.length);
    dout.write(toWriteBytes);
  }
  
  

  /** Writes an endpoint reference to the underlying stream */
  public void writeEprToStream(EndpointReferenceType eprType,
			       DataOutputStream dout) 
    throws IOException {

    if (eprType == null) {
      dout.writeInt(0);
      return;
    }
    
    EndpointReferenceDocument eprDocument =
      EndpointReferenceDocument.Factory.newInstance();
    eprDocument.setEndpointReference(eprType);
    
    String eprDocumentString = eprDocument.toString();
    writeStringToStream(eprDocumentString, dout);
  }


  /** Read an EPR from the underlying datainput stream */
  public EndpointReferenceType readEprFromStream(DataInputStream din) 
    throws IOException {
    EndpointReferenceType eprType = null;
    String eprDocString = readStringFromStream(din);
    
    if (eprDocString == null) {
      return eprType;
    }
    
    
    try {
      EndpointReferenceDocument eprDocument =
	EndpointReferenceDocument.Factory.parse(eprDocString);
      eprType = eprDocument.getEndpointReference();
    } catch (XmlException xmlEx) {
      System.out.println(moduleName + "Parsing Problems while un-marshalling" +
			 " EndpointReferenceType from the stream.\n" + xmlEx); 
    }
    return eprType;
  }


  /** Writes an envelope document to the underlying stream */
  public void writeEnvelopeToStream(EnvelopeDocument envelopeDocument,
				    DataOutputStream dout) 
    throws IOException {
    
    if (envelopeDocument == null) {
      dout.writeInt(0);
      return;
    }
    
    String envelopeString = envelopeDocument.toString();
    writeStringToStream(envelopeString, dout);
  }
  
  
  /** Reads an envelope document from the underlying stream */
  public EnvelopeDocument readEnvelopeFromStream(DataInputStream din) 
    throws IOException {
    EnvelopeDocument envelopeDocument = null;
    String envelopeString = readStringFromStream(din);
    
    if (envelopeString == null) {
      return envelopeDocument;
    }
    
    
    try {
      envelopeDocument = EnvelopeDocument.Factory.parse(envelopeString);
    } catch (XmlException xmlEx) {
      System.out.println(moduleName + "Parsing Problems while un-marshalling" +
			 " EnvelopeDocument from the stream.\n" + xmlEx); 
    }
    return envelopeDocument;
  }

}


